When I first started making jointed swimbaits, and used the Triple Trout as a starting point, I was fortunate enough to be working for a tournament trail that Bill Siemantel fished with his partner, Troy Lindner. I asked Bill to critique my lures, and I asked whether I was out of line using the Triple Trout as my "inspiration".
Bill said he had been involved over the years with every major sucessful West Coast swimbait builder, either helping in the design, or in testing their prototypes. He said, over the years, everyone copies someone else, dating back to a swimbait that was made in the '50s. I don't remember the name of the original, but he said, as long as you're putting your spin on something and not just making an exact copy, it is okay.
This is from one of the "silver eagles" of swimbait fishing, and bass fishing on the West Coast.
So, if you have the itch, go for it.
Be as original as you can be, and don't make duplicates of other people's stuff. Put your own spin on it and you'll be fine.
But it is, first and foremost, a business, so go into it, like Salty says, with your eyes open.